Johnson also won gold at the 2008 Paralympics in Beijing
Britain's disability swimmers captured nine medals on the final day at the IPC World Short Course Championships.
Their final tally of 46 over the seven days of competition in Rio de Janeiro left them in fifth place in the table.
Liz Johnson clocked a new world record in the women's 100m breaststroke and Stephanie Millward and Rhiannon Henry also claimed individual golds.
Millward, Claire Cashmore, Elizabeth Simpkin and Eleanor Simmonds also set a world best to win the 4x100m relay.
The British team finished the race in four minutes 56.23 seconds to take gold ahead of Russia and France.
It was a sixth gold of the meet for teenager Simmonds while Millward finished with eight medals, including four golds.
In the freestyle final she led from start to finish, beating the previous record set in the morning heats by over two-and-a-half seconds with fellow Briton Louise Watkin in third.
Johnson added short course gold to her Paralympic title in the SB6 100m breaststroke with an impressive victory in a new world record of one minute 38.82 seconds, beating her old record by two-and-a-half seconds.
Meanwhile, Henry broke her own British record in the 100m freestyle S13, defeating Australia's Prue Watt to win in 1:00.02.
Elsewhere, there was a surprise defeat for Sascha Kindred in his 100m breaststroke final as he finished second to Australian teenager Blake Cochrane with Britain also taking bronze through Thomas Young.
Sam Hynd also finished his campaign with a silver in his individual medley race.